1. Field of the Invention
The present invention relates to a colored anti-fog mirror.
2. Related Background of the Invention
Conventionally, halogen lamps have been used as vehicle headlights for automobiles and the like. The light emitted from a halogen lamp has a relatively weak light intensity in a short-wavelength bluish wavelength region, but a relatively strong light intensity in a yellow-to-red long wavelength region, for example around 800 nm.
If reflected light from a vehicle mirror excessively enters the eyes of a driver, then the driver is dazzled and is liable to get tired eyes.
To resolve this problem, as a vehicle mirror for coping with light from halogen lamp vehicle headlights, there has been developed a vehicle mirror using a colored anti-fog mirror whose mirror surface is colored blue, which is a complimentary color to yellow-red (see, for example, Japanese Patent Application Laid-open No. 2001-141916). This colored anti-fog mirror absorbs light in the yellow-red wavelength region, enabling the reflectance of light in this wavelength region to be reduced. As a result, the glare-reducing performance for reflected light from a vehicle mirror comprising the colored anti-fog mirror can be improved, and moreover visibility, in particular night visibility, can be improved.
Meanwhile, vehicle headlights comprising discharge lamps having a higher brightness than halogen lamps have become widespread in recent years. In contrast to halogen lamps, discharge lamps have an emission spectrum (bright line spectrum) over the whole visible region. If a vehicle mirror is made to absorb light in a specific wavelength region as in the case of the countermeasure against halogen lamps, then the reflected light for a discharge lamp thus becomes more intense in regions other than this specific wavelength region. For example, if the vehicle mirror is colored blue, then the reflected light from the mirror will have an amplified blue color. Such bluish reflected light dazzles people more than light of other colors. That is, a blue-colored vehicle mirror cannot be said to have an adequate anti-dazzle performance for discharge lamps.
Examples of mirrors that reduce reflected light in a specific wavelength region such as blue, i.e. short-wavelength, light are those described in Japanese Registered Utility Model No. 3021072, Japanese Utility Model Application Laid-open No. 62-114836, and Japanese Patent Application Laid-open No. 4-128803. For example, in Japanese Registered Utility Model No. 3021072, with the intention of providing an anti-dazzle mirror that enables glare to be reduced while maintaining visibility, there is proposed an anti-dazzle mirror having a first Cr film or Cr2O3 film that is formed on an upper surface of glass, a metal film that is formed on an upper surface of the first Cr film or Cr2O3 film and has a reflectance for a blue component out of three primary color components of light lower than the reflectance for the other color components, and a second Cr film that is formed on an upper surface of the metal film.